"""
两相流模型模块

该模块实现了两相流动所需的物理模型，包括：
1. 相间作用力模型
2. 壁面摩擦力模型
3. 传热模型
4. 相变模型
"""

import numpy as np
from typing import Dict, Optional, Tuple
from ..core.staggered_grid import StaggeredGrid

class TwoPhaseFlow:
    """两相流模型类"""
    
    def __init__(self, grid: StaggeredGrid):
        """
        初始化两相流模型
        
        参数:
            grid (StaggeredGrid): 交错网格对象
        """
        self.grid = grid
        
    def calculate_interfacial_forces(self) -> Dict[str, np.ndarray]:
        """
        计算相间作用力
        
        返回:
            Dict[str, np.ndarray]: 包含各方向相间作用力的字典
        """
        # 获取物理量
        alpha = self.grid.get_scalar_field('void_fraction')
        rho_l = self.grid.get_scalar_field('density_liquid')
        rho_v = self.grid.get_scalar_field('density_vapor')
        u_l = self.grid.get_axial_velocity_field()
        u_v = self.grid.get_axial_velocity_field()  # 简化处理,假设气液速度相同
        
        # 获取模型参数
        c0 = self.grid.get_model_parameter('drift_flux_c0')
        vgj = self.grid.get_model_parameter('drift_flux_vgj')
        
        # 计算相对速度
        u_r = c0 * (u_v - u_l) + vgj
        
        # 计算界面摩擦系数
        c_i = 0.44  # 简化处理,使用常数
        
        # 计算界面剪切力
        F_i = {
            'x': c_i * alpha * (1 - alpha) * rho_l * u_r * np.abs(u_r),
            'y': np.zeros_like(alpha)  # 简化处理,忽略横向界面力
        }
        
        return F_i
        
    def calculate_wall_friction(self) -> Dict[str, np.ndarray]:
        """
        计算壁面摩擦力
        
        返回:
            Dict[str, np.ndarray]: 包含各方向壁面摩擦力的字典
        """
        # 获取物理量
        alpha = self.grid.get_scalar_field('void_fraction')
        rho_l = self.grid.get_scalar_field('density_liquid')
        mu_l = self.grid.get_scalar_field('viscosity_liquid')
        u = self.grid.get_axial_velocity_field()
        v = self.grid.get_lateral_velocity_field()
        
        # 获取模型参数
        f_lam = self.grid.get_model_parameter('friction_coef_laminar')
        f_turb = self.grid.get_model_parameter('friction_coef_turbulent')
        
        # 计算雷诺数
        D_h = 4.0 * self.grid.dy  # 简化处理,使用通道间距作为水力直径
        Re = rho_l * np.abs(u) * D_h / mu_l
        
        # 计算摩擦系数
        f = np.where(Re < 2300, f_lam/Re, f_turb * Re**(-0.25))
        
        # 计算壁面摩擦力
        F_w = {
            'x': 0.5 * f * rho_l * u * np.abs(u) / D_h,
            'y': 0.5 * f * rho_l * v * np.abs(v) / D_h
        }
        
        return F_w
        
    def calculate_heat_transfer(self) -> Dict[str, np.ndarray]:
        """
        计算传热量
        
        返回:
            Dict[str, np.ndarray]: 包含各种传热量的字典
        """
        # 获取物理量
        alpha = self.grid.get_scalar_field('void_fraction')
        rho_l = self.grid.get_scalar_field('density_liquid')
        k_l = self.grid.get_scalar_field('conductivity_liquid')
        cp_l = self.grid.get_fluid_property('liquid_cp_ref')
        T_w = self.grid.get_boundary_condition('wall_temperature')
        T = self.grid.get_scalar_field('temperature')
        q_w = self.grid.get_boundary_condition('wall_heat_flux')
        
        # 获取模型参数
        h_sp = self.grid.get_model_parameter('single_phase_htc_coef')
        h_nb = self.grid.get_model_parameter('nucleate_boiling_coef')
        
        # 计算单相对流传热
        q_conv = h_sp * (T_w - T)
        
        # 计算核态沸腾传热
        dT_sat = T - self.grid.get_fluid_property('reference_temperature')
        q_boil = h_nb * dT_sat**3
        
        # 计算总传热量
        q_total = {
            'convection': q_conv,
            'boiling': q_boil,
            'wall': q_w
        }
        
        return q_total
        
    def calculate_phase_change(self) -> Dict[str, np.ndarray]:
        """
        计算相变率
        
        返回:
            Dict[str, np.ndarray]: 包含质量、动量和能量相变源项的字典
        """
        # 获取物理量
        alpha = self.grid.get_scalar_field('void_fraction')
        rho_l = self.grid.get_scalar_field('density_liquid')
        rho_v = self.grid.get_scalar_field('density_vapor')
        h_l = self.grid.get_scalar_field('enthalpy')
        h_fg = self.grid.get_fluid_property('latent_heat')
        q_w = self.grid.get_boundary_condition('wall_heat_flux')
        
        # 计算相变率
        Gamma = q_w / h_fg
        
        # 计算相变源项
        source_terms = {
            'mass': Gamma,
            'momentum_x': Gamma * (rho_v - rho_l),
            'momentum_y': np.zeros_like(Gamma),
            'energy': Gamma * h_fg
        }
        
        return source_terms